This invention relates to a nozzle cap for a trigger actuated pump sprayer, and more particularly to such a nozzle cap bi-injected of two different materials for enhancing and highlighting information and indicia provided on the cap to inform the operator of a specific rotative cap position, and for establishing an anti-slip finger grip in operation.
Trigger actuated pump sprayers are well-known as typically mounted to containers of chemical cleaner or the like for household use. The trigger sprayer is normally grasped by the operator and is actuated by pulling on the trigger lever for reciprocating the pump piston to discharge the liquid product from a pump chamber through a discharge passage and discharge orifice onto the target. The discharge orifice is typically formed in a nozzle cap mounted at the nozzle end of the discharge passage for rotation about the central axis of the cap. The nozzle cap may be snap mounted in place for manual rotation without axial movement between on and off positions, the cap comprising first and second pairs of flat outer surfaces together defining a rectangular nozzle cap body in cross-section. Spin mechanics within the pump body at the nozzle end are designed such that, in two opposed rotative positions of the cap, the discharge is placed in an off position, and in two opposed rotative other positions of the cap, the discharge is placed in one of two ON positions. The ON positions are typically STREAM and SPRAY. U.S. Pat. No. 4,706,888, commonly owned herewith, discloses such spin mechanics in cooperation with the nozzle cap as aforedescribed, and is incorporated herein by reference.
The flat outer surfaces of the walls of the cap are typically provided with indicia such as OFF on the first pair of opposed walls, and such as STREAM and SPRAY on a second pair of opposed walls, to identify the two OFF and the two ON rotative positions of the cap. Such indicia may be provided during the injection molding of the cap such that the markings OFF, STREAM, SPRAY are formed using the same thermoplastic material as the remainder of nozzle cap but are slightly raised from the outer surface of each flat wall of the cap. The indicia is thus formed as a relief on each of the four flat surfaces of the cap to highlight the indicia for the benefit of the operator.
The advantage of such a prior technique in nozzle cap production is low cost in that the indicia are formed in a single contemporaneous step during the molding operation. The prior art nozzle cap is, however, disadvantaged in that indicia or the lettering on the flat side walls of the cap are of the same thermoplastic material as the remainder of the cap and therefore cannot be contrasting to enhance visibility of the indicia.
Moreover, the thermoplastic material from which the indicia is formed is typically slippery when handled with wet hands which often occurs during use of the trigger sprayer and, because of the relatively small size of the nozzle cap for especially users having large hands, it becomes difficult for the user to securely grip the cap when holding an opposing pair of side walls to effect cap rotation.
The indicia referenced above such as OFF, SPRAY, STREAM are often-times replaced by indicia in the form of international symbols such as X for OFF, dots or the like forming a narrow cone to indicate a STREAM and dots or the like forming a wide cone to indicate a SPRAY. Or, a foreign language or symbol may be provided as indicia applied to the nozzle cap of a trigger sprayer. Also, it is known to provide the indicia to the nozzle cap by stamping or otherwise applying the indicia to a flat smooth outer surface of each wall of the cap wherein the stamped indicia may be applied in a color which contrasts from that of the cap itself. The stamping is typically not raised above the flat smooth surface of the wall of the cap, but since it is contrasting, it provides a clear indication of the rotative position of the cap for the user. Nevertheless, such an approach is disadvantaged in that the cap requires a two-step process for its manufacture, which only adds to the cost of production in time and materials.
It would be desirable to improve upon the nozzle cap to enhance the grippability of the walls of the cap and to improve upon the visibility of the indicia, in such a manner as to preserve low cost at high production speeds.
It is an object of the present invention to improve upon the manually rotatable nozzle cap of trigger actuated pump sprayers to render the sprayer easier to use and handle when manipulating the nozzle cap between its ON and OFF positions. The relief impressions applied to the outer faces of the flat walls of the nozzle cap bearing indicia relating to ON and OFF positions of the cap, are to be improved upon to render the indicia more visible and more tactile in feel, resulting in anti-slippage when handled if wet and improving upon the gripping action of the nozzle cap for rotating it between its ON and OFF positions. This objective is to be achieved utilizing a one-step operation in the production of the nozzle permitting high production speeds at low cost.
In carrying this general objective, the nozzle cap according to the invention is produced utilizing a known bi-injected technique of multimaterial injection molding in which a blank is molded from a first thermoplastic material whereafter it is permitted to cool to assure that it may function as mold whereafter a further thermoplastic material is co-injected into the mold formed by the first material such that the two materials are firmly welded together.
Further according to the invention, the second thermoplastic material may be of a different color and/or more elastic than the first thermoplastic material, so as improve upon the nozzle cap to enhance the indicia to render it more recognizable and/or less prone to slippage.
The second thermoplastic material co-injected to form the indicia may be raised from the outer surface of the flat wall of the nozzle cap in which it is formed to enhance both the tactile feel and to increase the anti-slippage characteristic of the cap.
Other objects, advantages, and novel features of the invention will become more apparent from the following detailed description of the invention when taken in conjunction with the accompanying drawings.